Prismatic double telescope.



H. JACOB. PRISMATIG DOUBLE TELESCOPE. APPLICATION FILED JULY 16, 1907.

898,653, Patented Sept. 15, 1908.

UNITED STATES PATENT oEEIcE.

HEINRICH JACOB, OF STEGLITZ, NEAR BERLIN, GERMANY, ASSIGNOR TO THE FIRM OF OPTISOHE ANSTALT C. P. GOERZ AKTIENGESELLSOHAFT, OF FRIEDENAU, NEAR BERLIN,

GERMANY.

PRI SMATIG DQUB LE TELESCOPE.

Patented Sept. 15, 1908.

Application filed July 16, 1907. Serial No. 383,959.

To all whom it may concern:

Be it known that I, HEINRIcH JAcoB, a citizenof the German Empire, and resident of Steglitz, near Berlin, Germany, engineer, have invented certain new and useful Improvements in Prismatic Double Telescopes, of. which the following is a specification.

This invention relates to prismatic double telescopes or field-glasses, the members or barrels of which are hinged to, each other, so that they can be adjusted to suit the distance between the users eyes and the purpose of the invention is to provide an instrument of this type which can be used while the user is holding his head in a convenient, somewhat inclined position. To allow of using the instrument in this manner, that is to say with the head downwardly inclined, or with the eyes directed downwards, the lines of sight of the telescope members must be other than straight. For this purpose the ocular-tubes are inclined with regard to the axes of the objective lenses. In order that the lines of sight of the two telescopes remain parallel with all adjustments of the distance between the telescopes the present invention provides that the ocular tubes, which are inclined with regard to the objective axes, are capable of rotation relatively to the barrels of the telescopes and are connected to guides by which they are kept parallel during the movement -mem of the barrels about the pivotal axes of the hinge-joint.

A construction embodying the invention is shown in the annexed drawing, in which Figure 1 is an elevation of the instrument, Fig. 2 a cross-section thereof, and Fig. 3 a longitudinal section of one of the telescopes, takenperpendicular to the plane containing the axes of both objectives.

The barrels a of the two telesco es are fixed to'hinge-pieces of'arms b rotata le on a s indle c, and contain the object-glasses (if he ocular tubes e are fixed to the prismholders or prism-chambers f and are inclined to the axes of the barrels a and obj cot-glasses. The rism-holders f are carried by tubular hers g rotatable in the barrels a. Each ocular tube is rovided with a guide-member h, which is tu ular in the construction illustrated, and a tubular member 11 is inserted into the guide-members h. Screws m are screwed into the outer ends of the members It and carry niits l which co-act with abutments 7c screwed into the ends of the member 1', to limit the relative movement of the barrels a. A milled-headed screw n serves in the known manner for adjusting the tubes g in the barrels a for the purpose of obtaining the known manner by rotating the hinged arms I; about the spindle 0. During this rotation of the said arms the barrels a are rotated relatively to the tubular parts 9, since the parts it and t', which allow relative lateral movement of the parts y, do not allow rotation thereof. The distance between the eyepieces can be increased until the nuts 1 meet the abutments 7c, this being the position shown in Fig. 2.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is:

1. In a prismatic double telescolpe comprising two telescope barrels provi ed with object glasses, said telescope barrels connected to each other by a hinge-joint, ocular tubes capable of rotation relative to the telescope-barrels and inclined with regard to the axes of the object-glasses and the pivotal axis of the hinge-joint, and means of preserving parallelism of the axes of said ocular tubes when the telescope barrels are ad usted relatively to each other by rotation about said pivotalaxis. v

2. In a prismatic double telesco e comprising two telescope barrels provi ed with object-glasses, said telescope barrels connected to each other by a hinge-joint, ocular tubes capable of rotation relative to the telescope barrels and inclined with regard to the axes of object-glasses and the plvotal axis of the hinge-joint, rectilinear guide members, each ocular tube firmly connected w1th one of said guide members, guiding means coopcrating with said ocular tubeguide members and adapted to keep same permanently In alinement with each other.

3. In a prismatic double telescope comprising two telescope barrels provided with object-glasses, said telesco 'e barrels connected to each other by a ge-joint, ocular tube members each comprising two parts arranged at an angle with relation to each other, the part remote from the eye-piece rotatably mounted on the corresponding telescope barrel, rectilinear guide members, each ocular tube member firmly connected with one of said guide members, guiding means cooperating with said ocular tube guide members and adapted to keep same permanently in alinement with each other.

4. In a prismatic double telesco e comprising two telescope barrels provi ed with object-glasses, said telescope barrels connect- ;d to each other by a hinge-joint, ocular members each comprising two tubular parts arranged at an angle with relation to each other and an intermediate prism chamber, the tubular part remote from the eye-piece being rotatably mounted on the corresponding telescope barrel, rectilinear guide members, each ocular member firmly connected with one of said guide members, guiding means 006 erating with said ocular tube guide mem ers and adapted to keep same permanently in alinement with each" other.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

v HEINRICH JACOB. Witnesses:

HENRY HAsPER, WOLDEMAR HAUPT. 

